In some buildings, such as shopping centers or hotels, many people are accommodated in a small space. This leads to the difficulty in providing data services for all these people which make it possible to connect the subscribers at a sufficiently high speed. An additional complication is that, because of a lack of glass surfaces, shopping centers for example can only be covered poorly by external base stations. Meanwhile, a similar set of problems also occurs in buildings which do have large-area glass surfaces but in which these glass surfaces are covered with various metal layers (for example copper layers) so as to minimize the cooling or heating of the building by external weather effects. This increases the heat transmission resistance, making it possible to reduce power costs for cooling or heating. However, the use of coatings of this type which have a shielding effect is associated with worse mobile communications reception in the interior of the building.
For this reason, a transition is being made to installing appropriate mobile communications antennas inside shopping centers, office buildings and hotels.
In known installations, merely the transceiver unit or BBU is operated locally, in other words inside the building or campus. All the other units required for a mobile communications connection are still operated centrally with the service provider. This means that both a connection for the control plane and a connection for the user plane or data plane have to be transmitted centrally to the service provider.
A configuration of this type requires a suitably wide-band connection to the service provider. This is even more complex if a plurality of mobile communications providers wish to provide their services within the same building.
Example non-limiting implementations herein therefore provide a mobile communications transmission system by means of which a multiplicity of mobile communications cells can be provided in a building or campus, it being intended for the installation costs to be lower than in currently used systems. A campus means a plurality of adjacent and/or associated building complexes and optionally also the area directly between these building complexes.
In some non-limiting embodiments, the mobile communications transmission system comprises at least a first baseband unit and a first gateway device, the first baseband unit being connectable or connected via the first gateway device to a data network, in particular the Internet. Via the first gateway device, user data are transmitted into and out of the data network. At least one transceiver unit is directly or indirectly connected to the first baseband unit. For a direct connection the transceiver unit is connected directly to the baseband unit, whereas for an indirect connection a processing and/or distribution device (for example HUB) is connected in between. The at least one transceiver unit is configured to provide at least a first mobile communications cell. By way of this first mobile communications cell, information can be exchanged with at least one subscriber device at or close to the building via a mobile communications connection. Via this mobile communications connection, a data connection between the at least one subscriber device and the data network is established via the first baseband unit. The mobile communications transmission system further comprises a first control device which is connected to the first baseband unit and the first gateway device. The first baseband unit and the first gateway device are installed in the building or campus in which the at least one transceiver unit provides the at least one first mobile communications cell. The first control device is accommodated at the base, in other words at an operating company remote from the building or campus of the first baseband unit, the at least one transceiver unit and the first gateway device. This means that the first control device is arranged outside the building or campus.
A connection to the Internet is provided locally, in other words from the building or campus. The data which the subscriber device wishes to transmit to the Internet no longer have to be routed via the operating company. In the simplest case, for this purpose a (V)DSL, connection on the site of the building or campus could be used, via which the data connection of the individual subscriber devices within the building or campus to the Internet is established. Merely the control device, which is also the control plane, is kept centrally at an operating company. This control device is for controlling not only the one first baseband unit, but preferably a plurality of baseband units in different buildings. The volume of data accumulated for this purpose is much less than the volume of data transmitted to and received from the data network, in other words the Internet, by the subscriber devices. Therefore, the connection to the operating companies, via which only the control data are transmitted, can be much narrower-band than the connection to the data network. This leads to a significant cost reduction.
The mobile communications cells are preferably LTE (long-term evolution) communications cells. In this case, the first control device comprises a first mobility management entity (MME) and a first home subscriber server (HSS). By contrast, the first gateway device comprises a first serving gateway (S-DW) and a first packet data network gateway (PDNGW).
The first control device preferably further comprises a first authentication, authorization and accounting device (for example a 3GPP AAA server).
Via the MME and the HSS, the subscriber device inside or close to the building is identified and authorized. The MME is connected to the HSS and simultaneously to the baseband unit and the serving gateway. The subscriber device can only transmit data via the serving gateway to the packet data network gateway if said device is positively authenticated and authorized.
The at least one subscriber device is preferably an access point. The at least one access point is configured to communicate via the first mobile communications cell with the at least one transceiver unit. This mobile communications connection may also be referred to as a backhaul connection. The access point is further configured to provide a WLAN connection (IEEE 802.11) for at least one mobile terminal. The first MME is thus configured to authorize access from the at least one access point via the first mobile communications cell and the first baseband unit and the first serving gateway and the first packet data network gateway to the access gateway. The access gateway is optional and may be downstream from the packet data network gateway. The first control device preferably further comprises an accounting system which is connected to the access gateway and the authentication, authorization and accounting system. The accounting system is configured to control the access gateway in such a way that the at least one mobile terminal can transmit data to the data network via the WLAN connection of the at least one access point. For this purpose, the mobile terminal has to authenticate itself to the access gateway. For example, in the simplest case, the access gateway may preceded by a password page, it only being possible to establish a connection to the data network once the correct password is entered. It is also possible to use an EAP-based method, in particular an EAP SIM (extensible authentication protocol SIM) method or an EAP AKA (authentication and key agreement) method, the mobile terminal transmitting the information contained in or acquired from the USIM (universal subscriber identity module), in particular the information required for identification, to the access gateway. This passes the conveyed information on to the accounting system, which is in turn connected to the authentication, authorization and accounting device. The authentication, authorization and accounting device validates this data with the authentication, authorization and accounting device of the mobile communications company with which the mobile terminal is registered. If validation is successful, the access gateway is unlocked, and the accounting takes place using the account with the mobile communications company.
It is particularly advantageous for the subscriber device to be an access point. This access point preferably likewise comprises a SIM card via which it authenticates itself to the first MME, whereby the access point is permitted to pass data to the packet data network. The access point itself in turn opens a WLAN (Wi-Fi) connection, whereby conventional mobile terminals, including for example laptops or smartphones, can establish a connection to the access gateway. It is particularly advantageous that there is no additional network wiring to the access points. This ensures lower installation costs, since in particular in large buildings the fire prevention requirements are easier to meet. It is merely necessary to establish a wired connection between the first baseband unit and the at least one transceiver unit. Preferably, an access point may for example be provided in each hotel room, and may in turn communicate with the at least one transceiver unit via a mobile communications connection, for example LTE or LTE-A or LTE Advanced Pro. As a result, it is possible to keep the signal strength of the access point in the room in question to a minimum while still providing excellent WLAN reception.
Because the accounting device is also accommodated centrally at the operating company, the administrative expense inside the building or campus for this purpose is kept to a minimum.
The first baseband unit is preferably operated by the company, which also operates the access points and provides the WLAN connection inside the building or campus. This company may also simultaneously be a mobile communications company. However, this does not have to be the case.
It is further possible for at least one second and/or at least one further baseband unit and a second and/or at least one further gateway device to be installed, the second and/or the at least one further baseband unit being connectable or connected to the data network via the second and/or the at least one further gateway device. This data network may be the same data network to which the first gateway device is connected. However, it may also be a further data network. The second and/or the at least one further baseband unit are directly or indirectly connected to the at least one transceiver unit. The at least one transceiver unit is in this case configured to provide a second and/or at least one further mobile communications cell. By way of these mobile communications cells, further subscriber devices internal to or close to the building can establish a data connection to the data network via the second and/or the at least one further baseband unit. This means that the at least one transceiver unit provides various mobile communications cells at different frequencies. The at least one transceiver unit, which in the simplest case is merely an antenna, is therefore configured to be appropriately wide-band. Further, in this embodiment, there is a second and/or at least one further control device, said devices being connected to the second and/or the at least one further baseband unit and/or to the second and/or the at least one further gateway device. The second and/or the at least one further baseband unit and the second and/or the at least one further gateway device are installed in the building or campus in which the at least one transceiver unit provides the multiplicity of mobile communications cells. By contrast, the second and/or the at least one further control device is accommodated remote from the site of the second and/or the at least one further baseband unit, at the same or at least one other operating company.
It is particularly advantageous that a plurality of baseband units can be connected to a transceiver unit. These further baseband units may be operated by different mobile communications companies. These baseband units provide signals at different frequencies, which are broadcast by the transceiver unit, resulting in a mobile communications cell being formed. In these further mobile communications cells, too, the components of the user plane are installed inside the building or campus, whereas the components of the control plane are accommodated centrally at the associated operating companies. As a result, for the user data a local Internet connection can be installed at the location of the building or campus, whereas the corresponding control data are conveyed to the operating company via the control plane via a narrower-band data line.
In a further embodiment, the second and/or the at least one further mobile communications cell are operated by the transceiver unit in a frequency range assigned to at least one mobile communications company which offers mobile communications services outside the building or campus. In this case, a user of the corresponding mobile communications company does not even notice that he has been registered with a mobile communications cell inside the building or campus. Calls and data services continue to be provided and are available.
In a further embodiment, the first mobile communications cell is not operated by a mobile communications company available at the location of the building or campus. It is therefore advantageous for the first mobile communications cell to be operated in a frequency range which is not used by mobile communications companies outside the building or campus.
The second and/or the at least one further control device likewise comprise a second and/or at least one further mobility management entity (MME) and a second and/or at least one further home subscriber server (HSS). The second and/or the at least one further control device further comprise a second and/or at least one further authentication, authorization and accounting device. Preferably, the authentication, authorization and accounting devices of all the control devices are interconnected for data exchange. As a result, for example, a customer of a mobile communications company can use the infrastructure of another mobile communications company, it being possible to account for the consumed data volume accordingly.
The second and/or the at least one further gateway device further comprise a second and/or at least one further serving gateway and a second and/or at least one further packet data network gateway. The second and/or the at least one further packet data network gateway are connected to the data network in this case, there is preferably no access gateway between the second and/or the at least one further packet data network gateway. Therefore, the second and/or the at least one further packet data network gateway are directly connected or connectable to the data network.
In a further embodiment, the mobile communications transmission system further comprises a processing and/or distribution device (central hub) which is connected to all the baseband units and to the at least one transceiver unit. The processing and/or distribution device is configured to pass on the signals generated by the first baseband unit to the corresponding at least one transceiver unit. Preferably, the processing and/or distribution device itself determines the corresponding transceiver unit to which the associated subscriber signal should be passed on.
The processing and/or distribution device is configured to pass on the signals received by the at least one transceiver unit from the first mobile communications cell or from the further mobile communications cells to the first baseband unit or the further baseband units. If a signal is received via the first mobile communications cell, it is passed on to the first baseband unit. The same applies to the received signals in the second or the at least one further mobile communications cell. These are passed on to the second or to the at least one further baseband unit.
The processing and/or distribution device may further be configured to amplify the amplitude and/or convert the frequency of a signal. This applies to signals which arrive from the at least one transceiver unit, as well as to signals which are generated by the associated baseband unit and are to be passed on to the at least one transceiver unit.
Preferably, there is a multiplicity of further transceiver units which are connected to the processing and/or distribution device and are configured to provide a multiplicity of mobile communications cells. Each transceiver unit can provide a plurality of mobile communications cells at different frequency ranges. These mobile communications cells are preferably configured as microcells, and cover a region having a diameter of less than 50 m, preferably of less than 40 m and more preferably of less than 30 m.
The at least one subscriber device may also be a further mobile terminal. In this case, the further mobile terminal is configured to establish a mobile communications connection to the second and/or the at least one further baseband unit via the second and/or the at least one further mobile communications cell. In this case, the access points would not be used. The further mobile terminals therefore use different mobile communications cells by comparison with the access points. The second and/or the at least one further mobility management entity are thus configured to allow access of the at least one further mobile terminal via the second and/or the at least one further mobile communications cell, the second and/or the at least one further baseband unit, the second and/or the at least one further serving gateway, and the second and/or the at least one further packet data network gateway to the data network.
In this case, it is particularly advantageous that, in the mobile communications transmission system according to example embodiments, known mobile communications companies and local LAN operators can both offer their services inside their building or campus without interfering with one another, these services being managed centrally outside the building or campus at the mobile communications companies or at the provider of the WLAN connection. As a result, the installation expense inside the building or campus can be kept to a minimum.